Hydraulic roof support control system
US4191498A · kind A · utility
6Cited by
11References
19Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 24, 1978 |
| Grant date | Mar 4, 1980 |
| Priority date | — |
| Expiry date | May 24, 1998 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21D23/16
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A hydraulic control system is provided for a roof support unit of an underground mining installation. The roof support unit is provided with a roof cap supported by hydraulic props. The control system comprises a valve for controlling the supply of pressurized hydraulic fluid to the props, and an actuator for closing the valve when the props have been retracted by a predetermined amount.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.